Aerosol–cloud interactions at the four candidate sites of the ANAtOLIA project

ANAtOLIA (Atmospheric monitoring to Assess the availability of Optical Links through the Atmosphere) is a European Space Agency project aimed at selecting sites for optical communication in the atmosphere. The main monitored parameters are cloud cover, aerosol in relation to atmospheric turbulence aimed at monitoring and forecasting the influence of aerosol and cloud cover in reducing optical communication through the atmosphere in selected sites by ESA. In this work, a novel algorithm that uses both the Pearson correlation coefficient and Fourier analysis is used to assess such influences. Aerosol and cloud cover data are obtained from ground stations and satellite over Calern (France), Catania (Italy), Cebreros (Spain), and Lisbon (Portugal). The novel algorithm provides a preliminary long-, medium-, and short-term aerosol–cloud interaction for these four candidate sites, obtaining respectively the variability, the seasonal, and hourly trend of the aerosol concentration; the main medium-term periodicities of aerosols as clouds precursors; the short-term correlation between morning-afternoon aerosol concentration. The use of aerosols as a precursor parameter of cloud cover through a Fourier analysis, makes the algorithm versatile and usable for all sites of optical communication and astronomical importance in which optical transparency is a fundamental requirement, and therefore it is a potential tool to be developed to implement forecasting models.